Heterodyne receiver for ultrashort waves



Dec. 31, 1940- E. GERHARD HETERODYNE RECEIVER FOR ULTRA-SHQRT WAVESFiled Oct. 15, 1938 Audio Frey Amp 1. Fre Amp/[flak 0 mmv H wE L m T6 8%V T fiA I MONA d m Patented Dec. 31, 1940 v I I l I l UNITED STATESPATENT OFFICE na'ranonynr. nnonrvnn FOB. ULTRA- snoa'r waves ErnstGerhard, Berlin, Germany, assignor to Telefunken Gesellschaft fiirDrahtlosc Telegraphic m. b. 11., Berlin, Germany,.a corporation ofGermany Application October 15, 1938, Serial No. 235,147 In GermanyNovember 11, 1937 7 Claims. (Cl. 250-9) The invention is concerned witha heterodyne the intermediate frequency transformer 8. The receiver setfor ultra-short waves in which a batterysfurmshesasuitable andpreferabiynegamagnetron serves simultaneously for the productive biasingpotential for the auxiliary electrodes. tion of the local oscillationand for mixing the It has been found that when the auxiliary eleclatterwith the incoming wave to produce an trades are negatively biased withrespect to the intermediate frequency wave. cathode, the control actionthereon is more pre- Heterodyne receivers are known in the prior 'cisebecause the electrons which pursue spiral art in which a magnetron isused to produce the courses under the influence of the magnetic fieldlocal oscillation. Mixing is effected in a separate tend to cluster inthe central portion of the rectifier tube. It is also known in the artthat discharge zone, whereas if the end-plates were 10 a magnetron tubemay be used to rectify the operated at zero bias or positive bias, theywould incoming signal waves, the modulation potential attract theelectrons so that an insufficient numbeing taken off between anode andcathode. As ber would reach the anodes to become effective animprovement upon the last-named circuit oras output energy of theoscillator tube. Finally ganization it has also been suggested to takeoff there is an amplifier I!) designed to amplify and 15 the modulationpotentials between separate auxrectify the intermediate frequency sothat the iliary electrodes and the cathode in order that modulation ofthe signal wave may be amplified the resonance properties of the rest ofthe tube by the device I 5 and made audible in the telemay remainunaffected by the potentials so taken phone receiver H.

30 on. The magnetron tube 1 is so adjusted that it In carrying out myinvention I preferably emwill generate oscillations whose frequency willploy an oscillation generator in combination with differ fromthe'frequency of the signal wave by a rectifier for producing anintermediate frean amount such as to produce the desired interquencywave by heterodyning with the incoming mediate frequency. As has beenascertained by signalling energy collected on an antenna system tests,an intermediate frequency voltage will then 25 designed for ultra-highfrequency reception. The be developed between the auxiliary electrodesand local oscillator and rectifier may be combined in the cathode. Thelocal oscillator wave, as known one magnetron discharge tube byinserting therein the art, may, of course, be used in turn as inso-called end plates. According to the method a transmitter wave so thattwo-way communica- 30 of the invention the intermediate frequencyouttion is feasible without circuit changes or changeput is derived froma, circuit which interconnects overs. In this case, for the purpose ofmoduthe end plates and the cathode through a suitable lation of thetransmitter or carrier wave there are direct current source. The localoscillations are required in addition a microphone l2, battery producedin the magnetron discharge tube ciri3 and an audio-frequency transformerM. The 35 cuit which includes the cathode and the seglatter acts uponthe end plate potential and thus mented cylindrically formed anode oranodes. upon the frequency of the sending wave.

The sole figure of the drawing shows an exem- I claim:

plifled embodiment of the invention. An aerial l. A two-way heterodynetransmitting and re 3 is connected by way of an energy feeder comceivingapparatus for ultra-short waves compriso prising two down leads to theanode segments ing an oscillation generating magnetron discharge of themagnetron tube I. The anode D. C. potube having a linear cathode,cylindrically segt n ia s suppli d by wa o the radio-fr qu y mentedanodes and end plates, a mixer frequency ch k oil 4 whi h is Connectedto a i in circuit connecting the cathode to the end plates,

mem r disp s d a ss t e two nduct rs f a constant current source in saidcircuit arranged 45 a Le h w re ystem by which said down leads to applya negative bias to said end plates with are constituted. The fiilamentof the tube is respect to the cathode, means in said circuit atconnected with battery 5. The ma netic field i times operative tomodulate the magnetron-genset up by the two solenoids 6 and l of anelectroerated oscillations by a. low frequency, and fur- 60 magnet.Mounted within the tube are two auxther means insaid circuit operativeat other times 5 iliary electr des which are radially disp sed in todeliver an intermediate frequency which rereference to the filament.These auxiliary eleclt from th heterodyning of incoming ultratrodesare'the same as lateral or wing plates, short waves with saidmagnetron-generated which are interconnected inside the tube, their01111 13011 66 terminals being brought out and connected with 2, Anultra-high frequency radio apparatus comprising a magnetron dischargetube having a linear cathode, oylindrically segmented anodes and endplates, a dipole antenna and Leaner-wire transmission system individualconductors of which are respectively connected each to an appropriateone of said anode segments, means for producing a magnetic field in thedischarge zone of said tube, means including a direct current sourceconnected between the cathode and the anode segments for enabling saidtube to generate oscillations, a circuit connected between the oathodeand said end plates, means in said circuit for biasing the end platesnegatively with respect to the cathode, further means in said circuitfor applying modulationsto said tube, and still further means in saidcircuit for deriving an intermediate frequency output current as theproduct of heterodyning the oscillations locally generated with incomingsignalling energy collected by said dipole antenna.

3. In an ultra-high frequency communication system in which oscillationsare generated in a magnetron discharge tube having segmented anodes, alinear cathode and end plates, the method of conducting a two-waycommunication which comprises heterodyning incoming signalling enersywith the locally generated oscillations to produce at times intermediatefrequency wave potentials between the cathode and the end plates, and atother times impressing modulation potentials on said end plates therebyto radiate modulated high frequency energy from said system whendesired, and maintaining a constant negative bias on said end plateswith respect to said cathode.

4. Apparatus for heterodyne reception of ultrashort waves comprising amagnetron discharge tube having a linear cathode, cylindricallysegmented anodes surrounding the cathode, and end plates, means forcollecting said waves and applying them contraphasally to opposingsegmented anodes, means for producing oscillatory potentials betweensaid cathode and said end plates which beat with said waves, means fornegatively biasing said end plates with respect to said cathode, andmeans-for deriving intermediate frequency potentials between the cathodeand the end plates.

5. A duplex radiocommunicating station comprising apparatus as definedin claim 4 in combination with means for impressing low frequencymodulation potentials between the cathode and the end plates thereby toreverse the action of the means for collecting and applying theultrashort waves and to cause ultra-short wave signaling energy to beradiated.

6. An ultra-high frequency two-way communication system comprising a,magnetron discharge tube having segmented anodes, a linear cathode andend plates, means for generating oscillations in said tube, meansoperative at times for heterodyning incoming signalling energy with saidoscillations to produce intermediate frequency wave potentials betweenthe cathode and end plates, means operative at other times forimpressing modulation potentials on said end plates thereby to radiatemodulated high frequency energy from ERNST GERHARD.

